ES2228278A1 - Microporous crystalline zeolite material, zeolite itq-28, production method thereof and use of same - Google Patents

Abstract

The invention relates to a microporous crystalline zeolite material, zeolite ITQ-28, the production method thereof and the use of same. More specifically, the invention relates to a microporous crystalline zeolite material, ITQ-28, which, in the calcined state and in the absence of defects in the crystalline lattice thereof, manifested by the presence of silanols, is characterised by having empirical formula x (M 1/n XO 2 ): y YO 2 : SiO 2 , wherein: M is selected from H + , at least one inorganic cation with charge +n, preferably alkalines or alkaline earths, and a mixture of both X is at least one chemical element in oxidation state +3, preferably Al, Ga, B, Fe, Cr or mixtures thereof Y is at least a chemical element in oxidation state +4, which is different from Si, preferably Ge, Ti, Sn, V or mixtures of same x has a value of between 0 and 0.2 inclusive and y has a value of between 0 and 0.1 inclusive. The invention is further characterised in that the material as it is synthesised has an x-ray diffraction pattern with at least values of angle 2 (degrees) and the relative intensities given in table 1. The invention also relates to the method of preparing said material and to the use thereof in the conversion of organic compounds.

Description

Nature microporous crystalline material zeolitic (Zeolite ITQ-28).

Technical Field

The present invention belongs to the technical field of microporous crystalline materials of a zeolitic nature, useful as catalysts or catalyst components for transformation processes of organic compounds.

Background

Zeolites are crystalline materials microporous formed by a network of TO4 tetrahedra that they share all their vertices giving rise to a structure three-dimensional containing channels and / or dimensional cavities molecular. They are of variable composition, and T represents usually atoms with formal oxidation state +3 or +4, such as for example Yes, Ge, Ti, Al, B, Ga, ... When any of the atoms T It has an oxidation state of less than +4, the crystal lattice formed has negative charges that are compensated by presence in the channels or cavities of organic cations or inorganic In these channels and cavities you can also stay organic molecules and H2O, so, in general, the The chemical composition of zeolites can be represented by following empirical formula:

x (M_ {1 / n} XO_ {2}) \: \ y \ YO_ {2} \: \ z R \: \ w H2O

where M is one or several organic cations or inorganic charge + n; X is one or more trivalent elements; Y it is one or several tetravalent elements, generally Si; and R is one or more organic substances. Although through treatments postsynthesis can vary the nature of M, X, Y and R and the values of x, y, z, and w, the chemical composition of a zeolite (such and how it is synthesized or after calcination) has a range characteristic of each zeolite and its method of obtaining.

The crystalline structure of each zeolite, with a specific channel and cavity system, results in a pattern of characteristic X-ray diffraction, which allows differentiation each.

Many zeolites have been synthesized in presence of an organic molecule that acts as the directing agent of structure. Organic molecules that act as agents structure directors (ADE) generally contain nitrogen in its composition, and can lead to stable organic cations in The reaction medium.

The mobilization of precursor species during the synthesis of zeolites can be carried out in the presence of hydroxyl groups and basic medium, which can be introduced as ADE hydroxide itself; such as hydroxide of tetrapropylammonium in the case of zeolite ZSM-5. Also fluoride ions can act as mobilizing agents in synthesis of zeolites, for example in the patent EP-A-337479 describes the use of I-IF in H2O at low pH as a mobilizing agent of the silica for the synthesis of zeolite ZSM-5.

Description of the invention

In the present invention a new microporous crystalline material of zeolitic nature, identified as "ITQ-28 zeolite", and its method of preparation. This material, both in its calcined form and synthesized without calcining has an X-ray diffraction pattern which is different from other known zeolitic materials and, by Therefore, it is characteristic of this material.

The X-ray diffraction pattern of the material ITQ-28 as synthesized has been obtained by the powder method using a fixed divergence slit and using the Kα radiation of Cu. This diagram is characterized by containing at least 2 ángulo angle values (degrees) and relative intensities (I / I_ {0}) of the reflections plus  Intense shown in Table I, where I_ {0} is the intensity of the most intense peak to which a value of 100. The relative intensities have been expressed in the following terms: m = medium intensity (between 20 and 40%); f = strong intensity (between 40 and 60%) and mf = very strong intensity (between 60 and 100%).

TABLE I

2 \ theta (degrees) Intensity ± 0.5 (I / I_ {0}) 9.57 F 14.73 m 19.79 F 20.40 m 21.17 F 21.40 F 21.93 mf 22.96 mf 23.25 m 24.58 m 26.79 m

The material once calcined and in anhydrous state answer, to the general formula

x (M_ {1 / n} X0_ {2}): y YO_ {2}: SiO_ {2}

where x has a value less than 0.2, preferably less than 0.1; and has a value less than 0.1, preferably less than 0.05; M is one or several cations inorganic charge + n; X is one or more chemical elements of oxidation state +3 (Al, B, Ga, Fe, - Cr) and Y is one or more chemical elements with oxidation state +4 other than Si, such like Ge, Ti, Sn or V).

It is possible, however, depending on the method of synthesis and its calcination or subsequent treatments, the existence of defects in the crystalline network, which are manifested by the presence of Si-OH groups (silanoles). These Defects have not been included in the empirical formula above.

Table II shows the angle values. 2 the (degrees) and relative intensities (I / I_ {0}) of the more intense reflections of the powder X-ray diffractogram of ITQ-28 zeolite after being calcined to remove the organic compounds occluded inside, where d = weak intensity (between 0 and 20%); m = medium intensity (between 20 and 40%); f = strong intensity (between 40 and 60%) and mf = very strong intensity strong (between 60 and 100%).

TABLE II

2 \ theta (degrees) Intensity ± 0.5 (I / I_ {0}) 9.61 mf 9.91 F 14.85 m 19.87 d 20.49 d 21.16 d 21.32 d 21.55 d 22.08 m 23.13 F 24.84 d 26.72 m

It should be noted that the data of diffraction listed for this sample as simple lines or unique, can be formed by multiple overlaps or overlapping reflections that, under certain conditions, such as differences in crystallographic changes, may appear as resulting or partially resolved lines. Generally the changes Crystallographs may include small variations in the unit cell parameters and / or changes in the symmetry of the glass, without a change in structure. So, the positions, widths and relative intensities of the peaks depend to some extent the chemical composition of the material, as well as of the degree of hydration and crystal size. In particular, when the network is composed exclusively of silicon oxides and of aluminum, with a Si / Al ratio = 19 and has been synthesized in presence of fluoride anions using the quaternary ammonium cation 2,3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene as the structure managing agent, the zeolite ITQ-28 as synthesized presents a pattern of X-ray diffraction as shown in Figure 1. This diagram is characterized by angle values 2? (degrees) and relative intensities (I / I_ {0}) presented in the Table III, where d, m, f and mf have the same meaning as the table II.

TABLE III

2 \ theta (degrees) Intensity ± 0.5 (I / I_ {0}) 7.53 d 7.96 d 8.34 d 8.75 d 9.57 F 9.86 d 14.58 d 14.73 m 15.30 d 16.10 d 17.35 d 17.53 d 17.95 d 19.24 d 19.79 F 20.40 m 21.17 F 21.40 F 21.93 mf 22.96 mf 23.25 m 23.67 d 23.99 d 24.58 m 24.90 d 25.29 d 25.79 d 26.49 d 26.79 m 28.06 d 29.10 d 29.41 d 29.85 d 30.64 d 31.04 d 31.67 d 31.90 d 32.12 d 35.13 d 35.46 d 35.73 d

The X-ray diffraction pattern of the previous one ITQ-28 sample after being calcined at 580 ° C to remove the occluded organic compounds inside it shown in Figure 2. This diffractogram is characterized by 2 ángulo angle values (degrees) and relative intensities (I / I_ {0}) shown in Table IV, where d, m, f and mf They have the same meanings as in Table III. The comparison of the X-ray diffractograms corresponding to the zeolite ITQ-28 as synthesized and in state calcined show the great thermal stability of the material.

TABLE IV

2 \ theta (degrees) Intensity ± 0.5 (I / I_ {0}) 7.61 d 7.97 d 8.41 d 8.84 d 9.61 mf 9.91 F 13.30 d 13.49 d 14.70 d 14.85 m 15.55 d 16.20 d 18.00 d 19.27 d 19.87 d 20.49 d 20.61 d 21.16 d 21.32 d 21.55 d 22.08 m 23.13 F 23.38 d 24.07 d 24.84 d 25.42 d 25.98 d 26.72 m 27.26 d 28.27 d 29.26 d 29.64 d 29.96 d 30.70 d 31.07 d 32.10 d 35.58 d

The present invention also relates to ITQ-28 preparation method. This one takes to conducted in the presence of fluoride anions as a mobilizing agent for the precursor species and includes a heat treatment to temperature between 80 and 200 ° C, preferably between 130 and 200 ° C, of a reaction mixture containing a source of SiO2 (how, for example, tetraethylorthosilicate, colloidal silica, amorphous silica);  optionally a source of trivalent elements such as Al, B, Ga, Faith or Cr; one or more organic cations, among which is 2,3- [bis (N-methyl-N- methylene pyrrolidinium)] - trans-5-norbornene; a source of fluoride ions, preferably HF; and water. The Organic cations are added to the reaction mixture in the form of salt (for example, a halide) or hydroxide and, additionally, you can add a source of alkaline or alkaline earth ions, in hydroxide form or salt form.

Optionally it is possible to add a source of other or other tetravalent elements AND other than Si, preferably Ge, Ti, V or Sn. It should be taken into account that components of the synthesis mixture may come from different sources, and depending on these may vary times and crystallization conditions. In order to facilitate synthesis sometimes it may be convenient to introduce in some time of preparation, ITQ-28 crystals (between 0.01 and 20% by weight with respect to the set of oxides inorganic, preferably between 0.05 and 10% by weight) as crystallization promoters (seeded).

The organic cation 2,3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene  It is synthesized following the process represented in the following scheme.

one

In this process from acid chloride 2,3- (chloride dicarbonyl) -trans-5- norbornene and pyrrolidine the corresponding diamide (product A) is obtained which subsequently it is transformed into diamine (product B) and finally it is quaternized to give rise to iodide of 2,3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene  (product C).

The composition of the reaction mixture that gives place to obtain the ITQ-28 material has the following composition in terms of molar relationships:

r ROH \: \ s \ M_ {1 / n} OH \ : \ t \ X_ {2} 0_ {3} \: \ u \ YO_ {2} \: \ v F \: \ SiO_ {2} \: \ w \ H_ {2} 0

where M is one or several inorganic charge cations + n; X is one or more trivalent elements, preferably Al, B, Ga, Fe or Cr; Y is one or several tetravalent elements other than Si, preferably Ge, Ti, Sn or V; R is an organic cation, preferably 2,3- [bis (N-methyl-N-methylenepyrrolidinium)] - trans-5-norbornene; F is a source of fluoride ions, preferably HF, and the values of r, s, t, u, v and w vary in the ranges

r = ROH / SiO2 = 0.01-1.0, preferably 0.1-1.0

s = M_ {1 / n} OH / SiO2 = 0-1.0, preferably 0-0.2

t = X 2 O 3 / SiO 2 = 0-0.1, preferably 0-0.05

u = YO_ {2} / SiO_ {=} 0-0.1, preferably 0-0.05

v = F / SiO2 = 0.1-3.0, preferably 0.1-2.0

w = H 2 O / SiO 2 = 1-50, preferably 1-20

The heat treatment of the reaction mixture It can be done in static or with stirring of the mixture. One time Once the crystallization is finished, the solid product is separated by filtration or centrifugation and dried. Calcination after temperatures above 350 ° C, preferably between 400 and 900 ° C, causes the decomposition of the organic remains occluded in the inside the zeolite and the exit of these, leaving free the zeolitic channels

The material produced by this invention It can be pelletized according to known techniques, and it can be used as a component of catalytic cracking catalysts of hydrocarbons, catalytic hydro-cracking of hydrocarbons, alkylation of aromatics with olefins and in processes esterification, acylation, aniline reaction with formaldehyde in its acid form and / or exchanged with suitable cations.

Examples Example 1 Organic cation preparation 2,3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene

To a round bottom flask equipped with a reflux condenser and magnetic stirring 5 g are added (22.82 mmol) of 2,3- (dicarbonyl chloride) - trans-5-norbornene. The solution is cool in an ice bath and add 30 ml of a drop by drop pyridine solution containing 17.04 g (240 mmol) of pyrrolidine. Once the addition is complete, it is left stirring at 0 ° C for 4 h. The pyridine is evaporated in a rotary evaporator and 75 ml of 10% HC1 are added keeping stirring for 1 h. The solution is extracted 3 times with dichloromethane. The organic extract is dried with Na 2 SO 4, filtered and concentrated on a rotary evaporator to obtain product A (R: 72%).

To a round bottom flask equipped with a reflux condenser and magnetic stirring are added 25 ml of dry ether and 1.06 g (30.25 mmol) of LiAIH4. Then you add 4.36 g of the diamide A dissolved in 50 ml of dry ether drop a gout. Once the addition is complete, the reaction mixture is heat at reflux for 2 h. The reaction is cooled in a bath of ice and 1.5 ml of water is added followed by 1.5 ml of 15% NaOH. The resulting mixture is vigorously stirred for 0.5 h by filtration at then to remove the solid. The ether of the organic phase is it is removed in a rotary evaporator and the residue is treated with 25 ml of 10% HC1. TO It is then brought to alkaline pH and extracted again with ether. The ether phase is dried with Na2SO4, filtered and concentrate on rotary evaporator to give product B (R: 85%).

3.46 g is added to a round bottom flask (13.45 mmol) of the diamine B dissolved in 30 ml of ethyl acetate. 15.27 g (107.57 mmol) of methyl iodide are then added and Stir at room temperature for 24 h. After this time  compound C is formed as a solid which is collected by filtration and wash thoroughly with ethyl acetate (R: 96%)

Example 2 Dihydroxide Preparation 2,3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene

Iodide of 2,3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene  obtained according to example 1 is exchanged for hydroxide using an ion exchange resin according to the following procedure: 14 g (25.74 mmol) of cation iodide (product C) They dissolve in water. To the solution obtained is added 51.5 g of Dowex SBR resin and kept under stirring until the next day. Subsequently, it is filtered, washed with distilled water and we obtain a solution of di hydroxide of 2,3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene which is titrated with HC1 (aq.), using phenolphthalein as indicator, obtaining superior exchange efficiency at 90% The final solution contains 0.21 equivalents of hydroxide per 1000 g of solution.

Example 3 Preparation of zeolite ITQ-28

0.163 g of Al isopropoxide are added on 3.32 g of tetraethylorthosilicate (TEOS). Then they are added 39.8 g of a dihydroxide solution of 2, 3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene (R (OH) 2) containing 0.21 equivalents of hydroxide in 1000 g. The mixture is left evaporating under stirring until  complete elimination of ethanol from hydrolysis of TEOS plus the amount of water needed to reach the Final composition indicated. Finally, 0.33 g of a Hydrofluoric acid solution (50% HF by weight). The gel composition is:

SiO_ {2}: 0.025 Al_ {2} O_ {3} : 0.26 R (OH) 2: 0.52 HF: 7 H2O.

The obtained mixture is introduced in an autoclave provided with an internal polytetrafluoroethylene sheath and it heated at 175 ° C for 30 days in a stove equipped with a rotation system The X-ray diffractogram of the solid obtained when filtering, washing with distilled water and drying at 100 ° C it is shown in Figure 1 and presents the list of the most characteristic peaks which appears in Table III. Calcination at 580 ° C in air during 3 hours allows to eliminate occluded organic species. The boss X-ray diffraction of zeolite ITQ-28 calcined is shown in Figure 2 and presents the list of peaks more characteristic that appears in Table IV and indicates that the Material is stable during this process.

Example 4 Preparation of zeolite ITQ-28

They are added. 0.245 g of Al isopropoxide about 5 g of tetraethylorthosilicate (TEOS). Then 21 g are added of a dihydroxide solution of 2, 3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene (R (OH) 2) containing 0.6 equivalents of hydroxide in 1000 g The mixture is left evaporating under stirring until complete. elimination of ethanol from the hydrolysis of TEOS plus amount of water needed until the final composition is reached indicated. Finally, 0.50 g of an acid solution is added hydrofluoric (50% HF by weight). The composition of the gel is:

SiO_ {2}: 0.025 Al_ {2} O_ {3} : 0.26 R (OH) 2: 0.52 HF: 2 H2O.

The obtained mixture is introduced in an autoclave provided with an internal polytetrafluoroethylene sheath and it heated at 175 ° C for 20 days in a stove equipped with a rotation system The solid obtained by filtering, wash with water Distilled and dried at 100 ° C is ITQ-28.

Brief description of the figures

Figure 1 represents the list of peaks more characteristic of the X-ray diffraction pattern of the material, as synthesized, obtained according to example 3;

Figure 2 represents the list of peaks more characteristic of the X-ray diffraction pattern of the material of example 3 in a calcined state.

Claims (6)

1. A microporous crystalline material of zeolitic nature that it has, in a calcined state and in absence of defects in its crystalline network manifested by the presence of silanoles, the empirical formula x \ (M_ {1 / n} XO_ {2}) \: \ y \ YO_ {2} \: \ SiO_ {2} in the that M is H + or at least one inorganic charge cation + n X is at least one chemical element of state of oxidation +3, preferably selected from the group consisting of Al, Ga, B, Fe and Cr; And it is at least one chemical element with a state of oxidation +4 other than Si preferably selected from the group consisting of Ge, Ti, Sn and V; characterized because x has a value less than 0.2, preferably less than 0.1, and has a value less than 0.1, preferably less than 0.05, and and because the material, as synthesized, has a diffraction pattern of X-rays with at least angle values 2 the (degrees) and relative intensities 2 \ theta (degrees) Intensity \p.m 0.5 (I / I_ {0}) 9.57 F 14.73 m 19.79 F 20.40 m 21.17 F 21.40 F 21.93 mf 22.96 mf 23.25 m 24.58 m 26.79 m where m is an average relative intensity between 20 and 40% f is a strong relative intensity between 40 and 60%, and mf is a very strong relative intensity between 60 and 100%. 2. A microporous crystalline material of zeolitic nature according to claim 1, characterized in that, in a calcined state, it has an X-ray diffraction pattern with at least 2 ta angle values (degrees) and relative intensities (I / I_ {0})

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2 \ theta (degrees) Intensity ± 0.5 (I / I_ {0}) 9.61 mf 9.91 F 14.85 m 19.87 d 20.49 d 21.16 d 21.32 d 21.55 d 22.08 m 23.13 F 24.84 d 26.72 m where d is a weak relative intensity between 0 and twenty%, m is an average relative intensity between 20 and 40% f is a strong relative intensity between 40 and 60%, and mf is a very strong relative intensity between 60 and 100%. 3. A method to synthesize the material microporous lens of claim 1 or 2 wherein reaction mixture containing a source of SiO_ {2}, optionally a source from another or others tetravalent elements Y, preferably Ge, Ti, V, Sn, optionally a source of one or more trivalent elements X, preferably Al, B, Ga, Fe, Cr, optionally a source of inorganic cations M load + n, one or several sources of organic cation R, preferably 2, 3- [bis (N-methyl-N-methylene pyrrolidinium)] - trans-5-norbornene, a source of fluoride ions, and Water, it is subjected to heating with or without stirring at a temperature between 80 and 200 ° C, preferably between 130 and 200 ° C, until its crystallization is achieved, characterized in that the reaction mixture has a composition, in terms of molar ratios; between the ranges ROH / SiO 2 = 0.01-1.0, preferably 0.1-1.0 M_ {1 / n} OH / SiO2 = 0-1.0, preferably 0-0.2 X_ {2} O_ {3} / SiO_2 = 0-0.1, preferably 0-0.05 YO_ {2} / SiO_ {2} = 0-0.1, preferably 0-0.05 F / SiO 2 = 0.1-3.0, preferably 0.1-2.0 H2O / SiO2 = 1-50, preferably 1-20

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4. A method according to claim 3, characterized in that the organic cation 2,3- [bis (N-methyl-N-methylpyrrolidinium)] - trans-5-norbornene is added in the form of dihydroxide or in the form of a hydroxide mixture and another salt, preferably a halide. 5. A method according to claim 4, characterized in that an amount of crystalline material is added to the reaction mixture, preferably with the characteristics of the material of one of claims 1 and 2, as a crystallization promoter, said amount being comprised in the range 0.01 to 20% by weight with respect to the total inorganic oxides added, preferably 0.05 to 10%. 6. A process to convert feeds formed by organic compounds that involve the use of an active form of the material of claim 2 as catalyst.